QT DISPERSION AND SUDDEN UNEXPECTED DEATH IN CHRONIC HEART-FAILURE

Death in chronic heart failure (CHF) can be from progression of diseas e or sudden and unexpected. We have attempted to identify factors that predict sudden death in CHF. We followed up 44 patients with CHF for 12-50 (mean 36) months. 4 patients died of non-cardiovascular causes a nd were excluded from analysis. There were 7 sudden deaths (symptoms f or less than 1 h in a previously stable patient) and 12 from progressi ve CHF. Patients who died of progressive CHF had lower left-ventricula r ejection fractions and higher concentrations of atrial natriuretic f actor than the 21 survivors, but there were no differences in these va riables between survivors and those who died suddenly. However, the su dden death group had significantly (p<0.05) greater inter-lead variabi lity in the QT interval on the electrocardiogram (QT dispersion; 98.6 [95% CI 79.1-118] ms1/2) than survivors (53.1 [41.9-64.3] ms1/2) or th e group who died from progressive CHF (66.7 [51.8-81.6] ms%). QT dispe rsion is a marker of myocardial electrical instability. The associatio n of increased QT dispersion with sudden death suggests that patients at high risk of such death could be identified by means of this simple , reproducible test. This group might benefit from more intensive trea tment.